Would energy be saved if lightbulbs were formulated to flicker on and off fast enough so the human eye could?

Question

not detect it, yet the light stays on for less time. In other words, would it be more energy costing to keep a regular light bulb or to replace it with ones that flickers, to the specifications above?

Answer 1

Actually your lights flicker on and off already! It just happens so fast you don't perceive it.

When used on an alternating current system the voltage passes through 0 volts on its way from maximum positive to maximum negative voltage.

In the US we use 60 Hz power, meaning the voltage alternates at 60 cycles per second. Going from zero volts to peak voltage, back through zero to peak negative voltage and back to zero constitutes one cycle so for each cycle the voltage goes through zero twice. (If you look at one cycle there are actually 3 zeros but one of those zeros at the end belongs to the next cycle).

Way back in the early days of electricity the US used 25Hz power, meaning the voltage alternated at a rate of 25 cycles per second. This actually produced a noticible flicker in some bulbs.

To see this in action look at slow motion video of fluorescent lights or incandescent lights. The flicker is very noticeable especially with fluorescent lights that use a simple ballast. To prevent this from being particularly annoying most modern ballasts switch at several kilohertz and simply flash so fast that your eye doesn't perceive it. Incandescent lights aren't particularly so bad about this as the filament usually remains hot enough to not dim.

http://www.youtube.com/watch?v=TFiv_GBfx...

http://www.youtube.com/watch?v=YnMP1Uj2n...

Answer 2

Yes, incandescent light could use a device like a VFD for motors which could reduce wattage. But it is a light bulb. We make CF, cold cathode ray, MH that use 25 W but put out 100 w equivalent. You could use 130 volt bulbs, or even 240 volt European. But that would put out less light and more orange color output. Just think of using a new dimmer, which change voltage.

Answer 3

The amount of energy needed to run the system would consume more power than the amount saved. More so the constant on off of the bulbs would lead them to burn out much quicker.

Answer 4

I have a LED flashlight that pulses on-off, being off about 70% of the time. This is a hand crank light, so I  can see how long it lasts with continuous or pulsed. The pulsed light allows me to walk just over 1 km on a charging, while steady lighting allows me to walk about 500 metres.

Now, I can see just as far down the road with pulsed as with steady light. I can not say whether I could as readily read with pulsed light.

CFL or incandescent lights do not give any improvement that I have detected.

Answer 5

Good question and an interesting notion.  Not many Answer folks look that deeply into a problem.

well, unfortunately the answer is no.  Even though you could  configure a power source to work on that frequency ( >20 hz is my guess) traditional filament technology doesnt respond to high frequency.  Since the frequency of household electricity is already 60 hz and the bulb is unaware (doesnt respond) of it, dropping it to 20 or so wont change anything.

Now on to technology that could.

Right now the only lighting technology with a high enough ramp rate is the LED.  they switch on at extremely high speeds.  But...they also are not resistive and dont draw that much power.  so.  Scientists and Engineers are working to improve the emission side of LEDs and are making great progress.   I forsee LED taking over Compact Flourescents in the near future.

wer

Answer 6

you get the same effect with an electronic dimmer

Answer 7

i am not an expert but i know that the light is produced by the resistance that is provided by a thin piece of metal which is very fragile. also a typical lightbulb is prone to fault in about 3-4 month's worth of switch on's- and offs.

also electricity is a renewable energy source (we can make electricity using solar energy) it would be wiser to focus on water issues (this last paragraph is here becouse your screen name is green living =) )

Answer 8

i'm pretty sure it takes more energy to start things than it does to keep it running. because of the initial surge of energy that flows into the lightbulb when you first turn it on i think it uses more engery than keeping it on for a second. also the fuses wouldnt last long. you'd have to replace lightbulbs constantly. its better to just use on of the energy efficient lightbulbs out on the market now.

Answer 9

Nice idea. However, I think the next generation of energy efficient lighting will be LEDs. These are extremely efficient and operate on very low current - even less than the low watt compact fluoros. The American military already have LED headlights for their vehicles. One of the tests to evaluate these light took place at night in a clearing in Alaska as part of the low temperature testing. The vehicles drove into a clearing in the forest using normal headlights. Once the vehicles were stationary these lights were turned off. After a few moments the LED lights were turned on. According to eye witness accounts, the clearing lit up light daylight and they were able to look directly at the lights with no blinding effect. The US Military fully expect these light to last for a minimum of 30 years before they need changing - effectively the life time of the vehicle. You can get LED lights for your home, but as yet the only the military has access to the really good toys. Typical